1. Technical Field
The present disclosure relates to display devices, and particularly, to a backlight module for a liquid crystal display.
2. Description of Related Art
Liquid crystal display devices have many excellent performance characteristics, such as large-scale information display ability, easy colorization, low power consumption, long lifespan, no pollution associated therewith, and so on. Therefore, liquid crystal display devices are widely used. A typical liquid crystal display device generally includes a backlight module. The backlight module is used to convert linear light sources or point light sources, such as cold cathode ray tubes or light emitting diodes (LEDs, hereinafter), into area light sources with high uniformity and brightness.
Referring to FIG. 6, a typical backlight module 410 includes two light sources 411, a light guide plate 412, a reflective plates 413, a diffusing plate 414, a brightness enhancement plate 415 and a casing 416. The two light sources 411, the light guide plate 412, the reflective plate 413, the diffusing plate 414 and the brightness enhancement plate 415 are installed in the casing 416. The two light sources 411 are positioned adjacent to two opposite light incident surfaces 4121 of the light guide plate 412. The light guide plate 412 includes a bottom surface 4122 and a light emitting surface 4123. The reflective plate 413 is positioned facing towards the bottom surface 4122. The reflective plate 413 is configured for reflecting the light exiting from the bottom surface 4122 back into the light guide plate 412. The brightness enhancement plate 415 and diffusing plate 414 are sequentially positioned one on top of the other adjacent to the light emitting surface 4123. The brightness enhancement plate 415 is configured for improving the brightness of the light transmitted through the light emitting surface 4123. The diffusing plate 414 is configured for diffusing the light transmitting through the brightness enhancement plate 415.
However, the light output from the brightness enhancement plate 415 is usually concentrated on a small region. When the backlight module 410 is applied to a liquid crystal display, this may make the light crystal display have a smaller viewing angle, which is undesirable for the user.
Therefore, a backlight module is needed to overcome the above shortcomings.